1. Field of Invention
This invention relates generally to stools, chairs and other types of seating devices adapted to seat an individual, and more particularly to an interactive seating device which makes it possible for an individual to take a seat without having to lower himself to do so, and which thereafter assists the seated individual in getting up from the seat.
2. Status of Prior Art
Ergonomics or human factors engineering deals with the interaction between a manufactured device and an individual making use thereof, the engineering taking into account the capabilities and limitations of the user. Thus a device which is efficient from the standpoint of human factors engineering is said to be "user-friendly." This applied science comes into play in the design of control handles, cockpits, chairs and other devices which unless properly interfaced to the size, strength and shape of the human user, will not effectively carry out its intended purpose.
Designers of stools, chairs and other seating devices usually seek to factor into the design the capabilities and limitations of typical individuals who will make use of these devices. However, in this context, the term typical is misleading, for it fails to factor in a substantial percentage of potential users. In the modern age, the life expectancy of the average individual runs into the seventh decade, women generally having a life span a few years longer than men. As a consequence, a significant percentage of the population is composed of so-called senior citizens or retirees, a fair number of whom are relatively enfeebled or otherwise handicapped as compared to those who are middle aged or youthful.
It is for this reason that a chair or other seating device, which from a human factors engineering standpoint may be regarded as well designed, is only so with respect to users who are in reasonably good physical condition. The same seating device may be hazardous to an elderly or enfeebled individual.
The conventional, well-designed chair has a seat which comfortably accommodates the posterior of the individual and his thighs or hind limbs This seat is at an elevation relative to the floor, such that when the individual is seated, his legs are then more or less vertical and his feet rest on the floor. Because the level of the seat is well below that of the posterior of an erect individual, in order to sit down, the individual must lower himself to the level of the seat.
The act of crouching in order to be seated presents no problem to a person in reasonably good physical condition. Nor is it difficult for that individual, when seated, to get up from the seat, even though in doing so he must lift his weight. But these routine movements which a person in good condition carries out almost without thinking, may represent an obstacle course to an elderly, enfeebled or handicapped person.
If this person finds it too difficult to crouch in order to lower himself into a seat, he may instead find it easier to let go and just fall into the seat. But this free fall may result in a hair line fracture or other injury, particularly if the seat is uncushioned. Even more difficult is for this person, once he has succeeded in sitting down, is to later get up from the seat, for this lifting action may take more strength than he or she possesses.